1. Field of the Invention
The present invention relates to an optical fiber connector for connecting an optical fiber to a photoelectric element.
2. Description of the Prior Art
A conventional optical fiber connector is constructed as shown in FIGS. 25 to 28 for example.
FIGS. 25 and 27 arc perspective views of an optical fiber housing in different states. FIGS. 26 and 28 arc right side sectional views of the optical fiber housing, with some portions corresponding to those of FIGS. 25 and 27 removed respectively.
The optical fiber housing 1 is thin and hollow in construction. A threading portion 1b of a mounting element 4 for mounting a protective tube 3 of an optical fiber 2 is formed integrally with a grip portion 1 a provided on the rear end side of the optical fiber housing 1. A front end of the optical fiber 2 inserted in the tube 3 fitted to the mounting element 4 is inserted into the optical fiber housing 1. A small box-like hood 5 having an opened rear surface is slidably mounted along a guide recess 1d to a coupling portion 1c to be coupled to a module housing (not shown) provided on the front end side of the, optical fiber housing 1. Although not shown, an engaging mechanism is provided to the hood 5 and the coupling portion 1c so as to prevent the hood 5 from disengaging from the coupling portion 1c.
Two ferrules 6 receiving the front ends of two optical fibers 2 are provided within the hood 5 and mounted to the coupling portion 1c of the optical fiber housing 1. Two apertures 7 are formed in the front side surface of the hood 5 so that the tips of the ferrules 6 project therethrough out of the hood 5 when the hood 5 slides rearwardly. Before the rearward sliding of the hood 5, the ferrules 6 are housed completely within the hood 5 which protects the end surfaces of the optical fibers 2. The rearward sliding of the hood 5 causes the front ends of the ferrules 6 to project outwardly of the hood 5, permitting the connection between two photoelectric elements in the module housing and the end surfaces of the optical fibers 2 when the module housing not shown is coupled to the optical fiber housing 1.
Four elastic pieces 8 are formed integrally with the optical fiber housing 1, two of the elastic pieces 8 having upwardly urged front ends on the upper surface of the coupling portion 1c of the optical fiber housing 1, the other two having downwardly urged front ends on the lower surface. The front end of each elastic piece 8 is thicker than the rear end thereof, so that the front ends of the upper elastic pieces 8 protrude upwardly of the upper surface of the hood 5, and the front ends of the lower elastic pieces 8 protrude downwardly of the lower surface of the hood 5. Before the rearward sliding of the hood 5, as shown in FIG. 26, the rear surface of the hood 5 abuts against the front surfaces of the elastic pieces 8 to prevent the hood 5 from sliding rearwardly. This prevents the front ends of the ferrules 6 from protruding outwardly of the hood 5, thereby protecting the end surfaces of the optical fibers 2.
For connection of the optical fiber housing 1 to the module housing not shown, the front ends of the elastic pieces 8 are initially deformed against the urging force as long as they enter the inside of the hood 5, and then the front ends of the ferrules 6 protrude outwardly of the hood 5 by the rearward sliding of the hood 5 as shown in FIG. 28.
Elastic locking pieces 9 are formed integrally with the optical fiber housing 1 and extending rearwardly on right and left sides of the optical fiber housing 1. Each of the elastic locking pieces 9 has a projection 10 formed centrally thereof which engages the engaging portion of the module housing to hold the connection between the optical fiber housing 1 and module housing, the photoelectric elements housed in the module housing being connected to the front ends of the optical fibers 2 inside the protruding ferrules 6. For separating the optical fiber housing 1 from the module housing, the rear ends of the elastic locking pieces 9 are deformed to disengage the projections 10, and forward sliding of the module housing permits the module housing to be separated from the optical fiber housing 1.
Although not shown, when the module housing is separated, an elastic urging member provided between the optical fiber housing 1 and the hood 5 causes the hood 5 to slide forwardly, and the hood 5 returns to the state of FIG. 26 from the state of FIG. 28. The elastic pieces 8 are restored to the state before the deformation, and the rear surface of the hood 5 abuts against the elastic pieces 8. The ferrules 6 are held within the hood 5, thereby protecting the end surfaces of the optical fibers 2.
In the conventional optical fiber connector, the hood 5 is provided directly slidably to the coupling portion 1c of the optical fiber housing 1 and encloses the ferrules 6 to protect the end surfaces of the optical fibers 2 when both of the housings are separated. However, the end surfaces of the optical fibers 2 can be seen through the apertures 7 of the hood 5 although the ferrules 6 are housed completely within the hood 5. It has been impossible to completely protect the end surfaces of the optical fibers 2. If the optical fiber connector is placed in a high-temperature atmosphere for a long period of time, with the elastic pieces 8 deformed and the hood 5 moved rearwardly, the elastic pieces 8 are deformed non-elastically to lose its restoring force, resulting in the hood 5 easily moved and not functioning to protect the end surfaces of the optical fibers 2.
Further, dust is apt to collect in the guide recess 1d of the coupling portion 1c, hindering smooth sliding of the hood 5.